I have compiled a list of 18,000+ subreddits and added tags to them.
The tags were calculated based on the questions asked in the subreddit, so you wilp see multiple tags next to subreddits.
You can view the google sheet by going here
Link of google sheet -> https://docs.google.com/spreadsheets/d/1hXPcH3CAzz3gb08Wb9_tROvry99FdVb_dXh3Eps-rLI/edit?usp=sharing
If you like the list you can also checkout the list of available TLD's which are named after their corresponding subreddits -> https://subreddits.jainsiddhant.com/